/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package com.mworld.galaxy.base.service.account;

import java.io.Serializable;
import java.util.List;
import java.util.Map;

import javax.annotation.PostConstruct;

import org.apache.commons.lang3.StringUtils;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationInfo;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authc.SimpleAuthenticationInfo;
import org.apache.shiro.authc.credential.HashedCredentialsMatcher;
import org.apache.shiro.authz.AuthorizationInfo;
import org.apache.shiro.authz.SimpleAuthorizationInfo;
import org.apache.shiro.realm.AuthorizingRealm;
import org.apache.shiro.subject.PrincipalCollection;
import org.apache.shiro.util.ByteSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springside.modules.utils.Encodes;

import com.google.common.base.Objects;
import com.google.common.collect.ImmutableList;
import com.mworld.galaxy.base.shiro.authc.UsernamePasswordRolesToken;
import com.mworld.galaxy.bull.entity.LoginUseOnlyUser;
import com.mworld.galaxy.bull.entity.User;
import com.mworld.galaxy.bull.service.account.AccountService;
import com.mworld.galaxy.bull.service.account.LoginUseOnlyAccountService;

public class ShiroDbRealm extends AuthorizingRealm {

    protected LoginUseOnlyAccountService loginUseOnlyAccountService;
    protected static Map<String, AccountService> roleUserAccountServices;

    /**
     * 认证回调函数，登录时调用。
     */
    @Override
    protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken authcToken) throws AuthenticationException {
        UsernamePasswordRolesToken token = (UsernamePasswordRolesToken) authcToken;
        LoginUseOnlyUser user = loginUseOnlyAccountService.findUserByLoginName(token.getUsername());
        if (user != null) {
            // 如果当前用户不属于登录所需要的角色则不予登录
            List<String> requiredRoles = ImmutableList.copyOf(StringUtils.split(token.getRequiredRoles(), ","));
            if (!user.getRoleList().containsAll(requiredRoles)) {
                throw new AuthenticationException("当前用户所属的角色与要求的角色不符。[登录名=" + user.getLoginName() + "][要求="
                        + token.getRequiredRoles() + "][所属=" + user.getRoles() + "]");
            }

            byte[] salt = Encodes.decodeHex(user.getSalt());
            return new SimpleAuthenticationInfo(new ShiroUser(user.getId(), user.getLoginName(), user.getName(),
                    user.getRoles()), user.getPassword(), ByteSource.Util.bytes(salt), getName());
        } else {
            return null;
        }
    }

    /**
     * 授权查询回调函数, 进行鉴权但缓存中无用户的授权信息时调用.
     */
    @Override
    protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
        ShiroUser shiroUser = (ShiroUser) principals.getPrimaryPrincipal();
        LoginUseOnlyUser user = loginUseOnlyAccountService.findUserByLoginName(shiroUser.loginName);
        SimpleAuthorizationInfo info = new SimpleAuthorizationInfo();
        info.addRoles(user.getRoleList());
        return info;
    }

    /**
     * 设定Password校验的Hash算法与迭代次数.
     */
    @PostConstruct
    public void initCredentialsMatcher() {
        HashedCredentialsMatcher matcher = new HashedCredentialsMatcher(AccountService.HASH_ALGORITHM);
        matcher.setHashIterations(AccountService.HASH_INTERATIONS);

        setCredentialsMatcher(matcher);
    }

    @Autowired
    public void setLoginUseOnlyAccountService(LoginUseOnlyAccountService loginUseOnlyAccountService) {
        this.loginUseOnlyAccountService = loginUseOnlyAccountService;
    }

    @Autowired
    public void setRoleUserAccountServices(Map<String, AccountService> roleUserAccountServices) {
        ShiroDbRealm.roleUserAccountServices = roleUserAccountServices;
    }

    /**
     * 自定义Authentication对象，使得Subject除了携带用户的登录名外还可以携带更多信息.
     */
    public static class ShiroUser implements Serializable {
        private static final long serialVersionUID = -1373760761780840081L;
        public Long id;
        public String loginName;
        public String name;
        public String roles;
        private User user;

        public ShiroUser(Long id, String loginName, String name, String roles) {
            this.id = id;
            this.loginName = loginName;
            this.name = name;
            this.roles = roles;
        }

        public String getName() {
            return name;
        }

        /**
         * 本函数输出将作为默认的<shiro:principal/>输出.
         */
        @Override
        public String toString() {
            return loginName;
        }

        /**
         * 重载hashCode,只计算loginName;
         */
        @Override
        public int hashCode() {
            return Objects.hashCode(loginName);
        }

        /**
         * 重载equals,只计算loginName;
         */
        @Override
        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj == null) {
                return false;
            }
            if (getClass() != obj.getClass()) {
                return false;
            }
            ShiroUser other = (ShiroUser) obj;
            if (loginName == null) {
                if (other.loginName != null) {
                    return false;
                }
            } else if (!loginName.equals(other.loginName)) {
                return false;
            }
            return true;
        }

        public User getUser() {
            AccountService accountService = roleUserAccountServices.get(roles);
            if (accountService != null) {
                user = accountService.findUserByLoginName(loginName);
            }
            return user;
        }
    }
}
